SECRET in game

Where is the secret in this game. I know, that it exist, because there is a music, called "SECRET.mp3".
But I can't found it.

Well.. there are four.

* By "all the secrets found", I mean you have found and beaten Souleye's Secret level, activated both Funky modes (Funky Mode Lite and Super Funky Mode) and seen the De_Gophe picture.

Based on the "SECRET.mp3" you're referring to Souleye.

Thanx! It was very hard to reach end of soul eye's level 3 times and activate superfunky without alter gravity.
I also watched video on utube to know, where is that superfunky mode.

To trigger super funky mode, unless you are playing XH version, you need to use the code you learn by the end of Souleye's secret level. When you know that code and have it activated, I suggest searching around the right-most part of Nifflas' Forest.